[OpenJDK 2D-Dev] RFR: 8230672: Spec. for FontMetrics.getMaxAdvance is too prescriptive.

[Philip Race]

Updated webrev : http://cr.openjdk.java.net/~prr/8230672.1/
And CSR for review : https://bugs.openjdk.java.net/browse/JDK-8243566

-phil

On 4/24/20, 3:00 AM, Sergey Bylokhov wrote:
> On 4/23/20 10:00 am, Philip Race wrote:
>> I am not 100% sure what you are getting at, but maybe
>> "render each such character" could be rephrased as
>> "query the advance of each such character".
>>
>> But I would not point to charWidth() for this because
>> it is not adequate for all code points.
>>
>> Does that clear it up ?
>
> Yes it looks better.
>
>>
>> -phil.
>>
>> On 4/23/20, 9:49 AM, Sergey Bylokhov wrote:
>>> On 4/23/20 9:34 am, Philip Race wrote:
>>>> No, I don't see the relationship.
>>>>
>>>> charWidth() is accurate if you use the FontMetrics from the render 
>>>> context.
>>>
>>> If it is always accurate why it is not recommended in the new 
>>> documentation? Why we suggest to "render each such character".
>>>
>>>  299      * None of these are exposed and they are all 
>>> implementation details,
>>>  300      * and there is no practical way to determine this. An 
>>> application
>>>  301      * which needs a better estimate of the maximum advance, 
>>> and knows
>>>  302      * the subset of characters it expects to display could render
>>>  303      * each such character to find the widest, but as discussed 
>>> above,
>>>  304      * since the displayed width of a {@code String} is not 
>>> necessarily
>>>  305      * the sum of the advances the value needs to be used with 
>>> caution.
>>>
>>>>
>>>> -phil.
>>>>
>>>> On 4/23/20, 9:19 AM, Sergey Bylokhov wrote:
>>>>> Hi, Phil.
>>>>>
>>>>> Isn't all/some of the new text in getMaxAdvance() is also 
>>>>> applicable to charWidth()?
>>>>> If I read the current doc properly then it looks like the 
>>>>> charWidth() should return "advance"
>>>>> of some specific "advance", and getMaxAdvance() is "just" maximum 
>>>>> value of any possible
>>>>> results from the charWidth().
>>>>>
>>>>> On 4/22/20 12:49 pm, Philip Race wrote:
>>>>>> bug : https://bugs.openjdk.java.net/browse/JDK-8230672
>>>>>> webrev : http://cr.openjdk.java.net/~prr/8230672/
>>>>>>
>>>>>> Loosen up the spec. a lot to reflect reality.
>>>>>>
>>>>>> I considered deprecating the method but there isn't any easy 
>>>>>> replacement,
>>>>>> so it would just be annoying to old code.
>>>>>>
>>>>>> This will clearly need a CSR which I will draft once we agree on 
>>>>>> the text here.
>>>>>>
>>>>>> -phil.
>>>>>
>>>>>
>>>
>>>
>
>